There are a number of processes that may be applied to an image such as descreening, compression, segmentation, etc, which use multiresolution analysis. In this case, the image is divided into a number of frequency sub-bands, the process is applied to some of the sub-bands, and the sub-bands are recombined to form the processed image.
For color images, the problem is that running all of these processes for each color separation, along with other color conversions, results in a large amount of computational overhead. A method of reducing the amount of computation is needed.
An improved color image printing method is proposed for combining the aforementioned multiresolution representation of an image with the color conversions required for high quality printing. This is achieved by dividing the color conversion into two steps: a computationally complex 3-dimensional printer color correction step, applied to a lower resolution sub image; and a computationally simpler color space transformation step, comprising primarily 1-D functions, applied to the full resolution image. The computational cost is thereby reduced by applying the more difficult computation, color correction, to the sub image which has fewer image points.